1. Field of the invention
This invention relates to a microphone with a variable resistance switch.
2. Description of the related art
FIGS. 1 to 3 illustrate a conventional microphone switch 100 for a microphone which is adapted to be connected to at least a speaker system (not shown) The switch 100 includes a U-shaped mounting frame 1, and a slide member 2 that is disposed movably in the mounting frame 1, that is formed with two parallel grooves 201 at a bottom side, and that is movable between ON and OFF positions. A terminal member 3 is mounted in the mounting frame 1, and has aligned first, second and third pairs of conductive rails 301, 302, 303. A pair of conductive contact members 304 are fittingly and respectively received in the grooves 201, and are engageable with the first and second pairs of the conductive rails 301, 302 when the slide member 2 is at the ON position so as to complete a circuit in the microphone, and with the second and third pairs of the conductive rails 302, 303 when the slide member 2 is at the OFF position so as to short the circuit. The microphone is disadvantageous in that a relatively large noise is generally produced by the speaker system due to an abrupt change in the resistance of the circuit upon switching of the slide member 2 to the ON position.
Therefore, the object of the present invention is to provide a microphone with a variable resistance switch so as to overcome the aforesaid drawbacks.
According to the present invention, a microphone comprises: a housing; a terminal member disposed in the housing and including a plurality of spaced apart terminals; and a variable resistance switch. The switch includes at least an elongated resistance member disposed in the housing, extending in a longitudinal direction, and having opposite first and second ends connected to respective ones of the terminals. An elongated conductive member is disposed in the housing adjacent and parallel to the resistance member, and has one end connected to a respective one of the terminals. A slide member includes at least a resilient conductive wiper that is disposed in the housing and that is simultaneously and constantly in sliding contact with the resistance member and the conductive member so as to complete a circuit through the terminals, the conductive member, and the resistance member. The slide member is operable to move in the longitudinal direction between an ON position, in which, the wiper is in sliding contact with the second end of the resistance member, and an OFF position, in which, the wiper is in sliding contact with the first end of the resistance member. The wiper is slidable over the conductive member and the resistance member so as to linearly vary the resistance in the circuit when the slide member moves between the ON and OFF positions.